Orofacial cancer and its treatment can produce disfigurement, serious deficits in speech and numerous problems related to food and airway management. Preliminary research has demonstratad that a prosthetic approach to patient rehabilitation may lead to significant improvements in some or all of these areas. Namely, an artifical tongue specifically designed to improve speech and food management in a total glossectomy patient lead to a 25-30% improvement in the patient's conversational speech intelligibility, and eliminated the need for tube feeding. Further research which incorporates and elaborates the principles of speech analysis used in designing the prosthetic tongue could lead to improved speech in other orofacial cancer patients. In this research project, a small number of patients with total or partial glosssectomy, unilateral maxillectomy or more extensive unilateral facial excisions will be subjected to detailed speech and dental evaluations by a speech pathologist and a maxillofacial prosthodontist, respectively. Based on these evaluations, prosthetic appliances which enable each patient to more closely approximate normal vocal tract dynamics and/or acoustics during speech will be designed and fabricated. Analyses of the prostheses' effects on each patient's speech will be followed by revisions in prosthesis design when the data indicate further improvements in speech may be possible. Specific prosthesis variables to be investigated, in addition to size/shape parameters, include type of fabrication material utilized, and whether the prosthesis is solid or hollow. Results of the study are expected to provide information useful to refining and expediting the design of speech prostheses in selected orofacial cancer patients. Further, results will provide a data base critical to a larger-scale investigation into speech characteristics and the potential of prosthetic rehabilitation in other orofacial cancer patients, computer-implemented techniques of prosthesis design based or "a priori" acoustic and anatomical information regarding an individual patient and, in the case of glossal prostheses, the potential for a prosthesis capable of limited, active movement.